fix(*): add python 3 support.

Some changes:

- Fix import style

```python
from create import *

from .create import *
```

- Fix error: traceback.format_exc()
- import six to handle unicode difference between py2/3
- Add py32 to tox
- Replaced io.BytesIO with bytearray
Merge branch 'py3_support' of https://github.com/cabrera/falcon into py3_support